title: Probability of treatment following acute decline in lung function in children with cystic fibrosis is related to baseline pulmonary function.
abstract: OBJECTIVE
  To determine whether the association between high forced expiratory volume in 1 second (FEV1) and increased rate of decline in FEV1 in children with cystic fibrosis could be due to less frequent intervention after acute declines (sudden decline events) in FEV1.
  
  
  METHODS
  Patients with cystic fibrosis aged 6-17 years enrolled in the Epidemiologic Study of Cystic Fibrosis were assessed for a sudden decline event, defined as a 10% relative decline in FEV1% predicted from an average of 3 consecutive stable baseline spirometries. The likelihood of therapeutic intervention within 14 days before and 56 days after this event was then related to their baseline FEV1% predicted age-specific decile using a logistic regression adjusting for age group (6-12 years, 13-17 years) and presence of Pseudomonas aeruginosa on respiratory culture.
  
  
  RESULTS
  A total of 10 888 patients had at least 1 sudden decline event in FEV1. Patients in the highest FEV1 decile were significantly less likely than those in the lowest decile to receive intravenous antibiotics (OR, 0.14; 95% CI, 0.11-0.18; P < .001) or be hospitalized (OR, 0.18; 95% CI, 0.14-0.23; P < .001) following decline.
  
  
  CONCLUSIONS
  Children and adolescents with high baseline lung function are less likely to receive a therapeutic intervention following an acute decline in FEV1, which may explain their greater rate of FEV1 decline.
authors.affiliation: Department of Pediatrics, University of Arizona, Tucson, AZ. Electronic address: wmorgan@arc.arizona.edu.
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Morgan
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Wagener
authors.forename: Ashley
authors.initials: A
authors.lastname: Yegin
authors.forename: David J
authors.initials: DJ
authors.lastname: Pasta
authors.forename: Stefanie J
authors.initials: SJ
authors.lastname: Millar
authors.forename: Michael W
authors.initials: MW
authors.lastname: Konstan
mesh_terms: D000293:Adolescent; D002648:Child; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology; D008297:Male; D016017:Odds Ratio; D011336:Probability; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000503:physiopathology; D012044:Regression Analysis; D012129:Respiratory Function Tests / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
keywords: CF; Cystic fibrosis; ESCF; Epidemiologic Study of Cystic Fibrosis; FEV(1); Forced expiratory volume in 1 second; IV; Intravenous